In the past, silicon phthalocyanines generally have been made by the cyclization of a ring precursor. One such method involves reacting a diiminoisoindoline with a tetrachlorosilane. An example of this route is: ##STR1##
A disadvantage of this method is that it gives byproducts which are difficult to separate. The products are thus difficult to purify. Moreover certain phthalocyanine molecules are difficult, if not impossible, to assemble by this method.